Re: 2.6 vs 2.4, ssh terminal slowdown

From: MIke Galbraith
Date: Mon Feb 13 2006 - 00:49:24 EST


On Mon, 2006-02-13 at 16:37 +1100, Con Kolivas wrote:
> On Monday 13 February 2006 16:32, MIke Galbraith wrote:
> > On Mon, 2006-02-13 at 16:05 +1100, Con Kolivas wrote:
> > > On Monday 13 February 2006 15:59, MIke Galbraith wrote:
> > > > Now, let's see if we can get your problem fixed with something that can
> > > > possibly go into 2.6.16 as a bugfix. Can you please try the below?
> > >
> > > These sorts of changes definitely need to pass through -mm first... and
> > > don't forget -mm looks quite different to mainline.
> >
> > I'll leave that up to Ingo of course, and certainly have no problem with
> > them burning in mm. However, I must say that I personally classify
> > these two changes as being trivial and obviously correct enough to be
> > included in 2.6.16.
>
> This part I agree with:
> - } else
> - requeue_task(next, array);
> + }
>
> The rest changes behaviour; it's not a "bug" so needs testing, should be a
> separate patch from this part, and modified to suit -mm.

Well, both change behavior, and I heartily disagree. Blocking a 700ms
sleep while allowing a 100ms sleep to bypass the same checkpoint only to
then be multiplied by 10 is a bug.

Actually, the point at which a task becomes interactive is the point at
which scheduler semantics change. Ergo, as far as I'm concerned, this
should be a boundary which must be crossed before proceeding further.
That, I agree, would be a behavioral change which should be baked in mm.

-Mike

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